Film



Patented Feb. 23, 1937 UNITED STATES FILM Max Hagedorn and Armin Ossenbrunner, Dessau in Anhalt, and Gustav Wilmanns, Wolfen Kreis Bitterfeld, Germany,

Corporation, Binghamton, N. Y., a

I of New York assignors to Agfa Ansoo corporation No Drawing. Application March 2, 1934, Serial No. 713,770. In Germany March 4, 1933 2 Claims.

Our present invention relates to photographic film and more particularly to such a film with an improved support.

One of its objects'is to provide a photographic film with a support improved by the incorporation of a softening agent which has not been used for this purpose. Further objects will be seen from the detailed specification following,

hereafter.

The use of phosphoric acid esters of an alcohol which is derived from a fatty acid such as trioctylphosphate, diisoamylbutylphosphate, diethylphosphate, or butylphosphate as softening agents for cellulose derivatives is known. These softening agents have no dissolving action on cellulose derivatives and in contradistinction to the softening agents having a dissolving action on cellulose have a more favorable influence on the mechanical properties of the films made from cellulose derivatives.

According to this invention it has been found that softening agents having no dissolving action on cellulose ester and which are derived from vegetable oils containing the glycerides of fatty acids having from 8 tol l carbon atoms are particularly suited as softening agents for cellulose esters for the manufacture of supports of photographic films. Such oils are, for'instance, cocoa nut oil, palm nut oil, and laurel-oil. b As derivatives which are good softening agents there may be mentioned the esters of the mixture of fatty acids obtained by saponification of the glycerides with a monovalent alcohol; the esters of the alcohols obtained from the oils by simultaneous saponification and hydrogenation with aliphatic acids, or aromatic acids, or halogen hydracids, or phosphoric acid; the ethers of the aforesaid alcohols.

That the softening agents are suitable for the ;manufacture of supports for photographic films they must not contain strongly smelling compounds. For this reason, for instance, the esters of the mixture of fatty acids from the above mentioned oils with methyl alcohol or ethyl al 3 cohol are not suitable. Thus, there enters into consideration for the purposes of this invention only the esters of such a fatty acid and propyl alcohol or a higher alcohol, preferably an alcohol having more than 5 carbon atoms. The separation of compounds of low molecular weight which yield strongly smelling constituents may be effected by distillation in the vacuum before or 7 after conversion of the oils into their derivatives. For the same reason the nitriles of fatty "acids are useless.

Among the esters of the mixed fatty alcohols,

duction of the acid of cocoa nut oil boiling above 150. at a pressure of 13 mm. have proved suitable as softeners for nitrocellulose. The mixtures of softening agents are suitable for the preparation of films from cellulose nitrate and for films from organic cellulose ester, for instance, cellulose acetate; cellulose nitroacetate, cellulose acetobutyrate, cellulose butyrate and other technically useful cellulose esters. It is clear that not all of the products have the same action. A few experiments will be sufficient to ascertain which of the softeners suggested have the best effect for films made of a certain cellulose ester or a mixture of cellulose esters, to render it elastic and resistant to mechanical strain.

It has been found that the use of derivatives or the conversion products of a mixture of fatty acids is far superior to the use of chemically uniform products isolated from the mixtures of fatty acids. This is due to the fact that the precipitating action of derivatives with a long chain of carbon atoms on cellulose ester is particularly great and that the separation of the cellulose derivative on evaporation of the solvents would occur too abruptly when using a uniform highly molecular precipitant so that the film would easily become turbid or even white. When using a mixture of precipitants having various degrees of precipitating action the separation occurs slowly and gradually, whereby the film is prevented from becoming turbid or white, and the mechanical data, more particularly the creasing number and the elongation are improved. The conversion products of fatty acids with more than 14 carbon atoms have no longer the same good properties as softeners than have the conversion products of fatty acids with a number of carbon atoms between 8 and 14. Mixtures, containing a large amount of such fatty acids should therefore not be employed for the purpose in question.

The softeners for the manufacture of support for photographic films according to this invention can also be used in admixture with the softeners hitherto known for this purpose and even then an improved product will be obtained.

The, following examples illustrate the invention:

Example 1.-20 parts of nitrocellulose containing 12.2 per cent of nitrogen are dissolved in 100 parts of a'mixture consisting of 8 parts of acetone and 2 parts of ethyl alcohol while adding 2 parts of amyl ester of the acids from laurel oil containing 8 to 14 carbon atoms. The solution is cast in known manner to form a film of 0.130 mm. thickness. When tearing this film in Schoppers dynamometer, creasing it in Schoppers celluloid folder or testing it in Schoppers impact testing machine of the pendulum type, data are obtained which are superior to'those of a film which instead of the amyl ester of the'acid of the laurel oil, contains the usual addition of camphor (10 per cent).

Creasing Impact test Breaking number kilo cm./cc.

Elongaload kilo Kind of addition non 10 per cent of the amyl ester of the acid from laurel oil 101 75 247 10 percent of carnphor 100 i 24' 43 130 Percent 28 in a mixture of ether and alcohol (in proportion 3:1); 1.8 grams'of the alcohol obtained by reduction of the acids containing '8 to 14 carbon Example 3.To :a solution of nitrocellulose (according to Example 2) is added instead of the alcohols obtained by reduction of the acids from cocoa nut oil, an equal "amount of a mixture of monochloride of hydrocarbons obtainable by reacting on said alcohols with hydrochloric acid. The film has a high elongation and a high creasing number.

Breaking Elonga- Creasing Kmd load ki tion number Percent 10 percent of chloride 120 44. 5 343 percent of caphor 110 37. 0 88 Example 4.When adding to the solution (according to Example 2), instead of the mixture of alcohols from cocoa nut oil, an equal amount of its phthalic acid esters, a film having the follow- Example 5.200 grams of hydroxyethylcellu- 'lose acetate are dissolved in 667 cc. of methylene chloride, 46'? cc. of chloroform and 66 grams of amylalcohol with the addition of 10 grams of triphenylphosphate and 30 grams of softening agent obtained by esterifying the mixture of alcohols which results from saponification and reduction of cocoa nut oil with the fatty acids containing 8 to 14 carbon atoms obtained from cocoa nut oil by saponification. The solution is cast to form a film of 130 to 1501.0 thickness which has the following mechanical data:

Breaking load kilo/0.1 sq. cm.

Elongation Creasing number Percent Example 6.250 grams of cellulose acetate containing 56% of acetic acid are dissolved in 800 cc. of methylene chloride, 500 cc. of chloroform and 83 cc. of amylalcohol with the addition of 30 grams of diphenylphosphate having the last hydrogen atom esterified by the alcohols from cocoa nut oil and 10 grams of triphenylphosphate. This solution is cast to a film of 130 thickness which has the following mechanical data:

Breaking E1 C I t t load kilo/0'1 ongateasing mpoct es tron number kilo cm./cc.

Percent 85 34 179 293 Example 7 .200 grams of cellulose triacetate are dissolved in 200 cc. of methylenechloride and 100 cc. of methanol with the addition of 40 grams of a mixture obtained by etherification with benzyl alcohol of the alcohols obtained from the fatty acids having 8 to 14 carbon atoms present in laurel oil and containing as .principal constituent dodecylbenzylether. This solution is cast to form a film of 130;; thickness which has the folowing mechanical data:

Breaking Elonga- Creasing Impact tcst load k1lo/0.1

cm. tion number kilo cur/cc.

Percent 106 22 58 168 Our present invention is not limited to the foregoing examples or the specific details given therein but we contemplate as included all modifications and equivalents which fall under the scope of the appended claims.

What we claim is:

1. The process'of manufacturing a support for photographic layers which comprises dissolving cellulose acetate containing 56 per cent of acetic acid in a mixture of methylene chloride, chloroform and amylalcohol; adding as a softening agent diphenylphosphate havingthe last hydrogen atom'esterified by the alcohols containing 8 to 14 carbon atoms obtainable from cocoa nut oil, and triphenylphosphate and casting the solution to form a film.

2. A support for photographic layers comprising celluloseacetate containing 56 per cent of acetic acid and diphneylphosphate having the last hydrogen atom esterified by the alcohols containing 8 to 14 carbon atoms obtainable from cocoa nut oil. and triphenylphosphate.

MAX HAGEDORN. ARMIN OSSENBRUNNER.

GUSTAV WILMANNS. 

